Back pain is the number one cause of disability in industrialized nations. Research indicates that 80% of people in the United States will experience back pain at some point in their lives. While much back pain spontaneously subsides within 45 days of acute onset, pain which lasts more than 45 days is chronic due to the increases in difficulty ameliorating this pain. Furthermore, research has indicated then for prevention and reduction of chronic pain, isolated strengthening of the lumbar musculatures is vital. In some studies there has been more than an 80% success rate at reducing pain that is chronic following a course of intensive and isolated lumbar strengthening. These results are irrespective of pathological diagnoses as long as the diagnoses are not absolute contraindication for back exercise. Research indicates that devices which do not promote isolated lumbar motion may not be effective at providing strengthening benefits.
Typical back machines do not facilitate lumbar muscle exercise due to incongruent mechanics between the device itself and human users. In particular, typical back machines only have a single machine axis which is adequate if the machine is trying to accommodate the biomechanics of the elbow or the knee which has a simple axis. However, a single axis machine does not accommodate or encourage the spine to flex and extend when loaded and instead the torso simple rotates around the hip. Furthermore, typical back machines use very uncomfortable skeletal restraints to prevent the pelvis from of the user from rotating and thereby forces the spine to flex and extend.
Additionally, typical back machines rotate around a single axis or point like an oval or a circle. The machine rotates around that axis as in a circle, but that path of motion that is created is not congruent with spinal mechanics and as a result it inappropriately encourages the torso of the user to simply rotate around the hip joint circumventing the spinal function that is desirable.
An example of a machine which has been shown to effectively promote lumbar strengthening have incorporated elaborate and uncomfortable skeletal restraint mechanisms to essentially wrestle the user's anatomy into compliance with some degree of spinal motion and muscular loading is illustrated in FIGS. 1A and 1B.
In addition to the machine in FIGS. 1A and 1B being intimidating and uncomfortable these types of machines are very expensive (e.g. $40,000) making them effective but impractical.
In view of the above, what is needed is a back machine that utilizes three axes of rotation that work together in concert to offer a biomechanically adaptive work arm which enables the multi-segmental spine of a user to flex and extend and accommodates the radical shifts in virtual axes of motion about the spine by encouraging or allowing true spinal flexion and extension without the skeletal restraint. In other words, a back machine that fosters and facilitates isolated spinal flexion and extension exercise for the effective muscular loading of muscles that flex and extend the spine is needed.